Wellington - The All Blacks have made wholesale changes for their Rugby Championship clash with South Africa in Wellington on Saturday.
Kick-off is at 09:35 SA time.
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There are 10 changes to the run-on side and five on the bench in a strong All Blacks combination looking to extend their unbeaten record in the fourth round Rugby Championship match.
Ryan Crotty, Sam Cane and Rieko Ioane all made the starting line-up after missing last week's Test against Argentina because of injury.
"We know that we'll have to be at our very best," Hansen said when naming the side on Thursday, and noting that South Africa "will be desperate" following back-to-back losses to Argentina and Australia.
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He opted for Crotty to start in the 12 jersey, having been given the all clear after being knocked out against Australia early in the series.
Williams, who has had little rugby in recent months, will likely take the field in the second half.
The star midfielder missed the first two Tests against France in June following knee surgery, and played just 58 minutes of the third Test before injuring his shoulder and has been out of action ever since.
Aaron Smith and Beauden Barrett are reunited in the halves while Anton Lienert-Brown will play at outside centre.
Rieko Ioane returns from injury to the left wing, while Ben Smith moves to the right wing to make way for Jordie Barrett at fullback.
In the forwards, Sam Whitelock moves into the number four jersey, with Brodie Retallick injured, and Patrick Tuipulotu comes onto the bench as lock cover for his first Test of 2018.
Liam Squire and Cane return as flanks with Highlanders rake Liam Coltman promoted to back up hooker ahead of Nathan Harris.
"We've had a good week's preparation, focussing on what we need to bring to the game through our skill sets, the intensity of our play and our energy," Hansen said.
"We'll have to be at our very best in all these areas to counter an opposition we know will be desperate following their back-to-back losses. That means we'll have to respond with a quality performance and a real hunger to be better.
"You just have to look at our last encounter in Cape Town to understand what kind of beast we will be facing."
The unbeaten All Blacks lead the Rugby Championship with 15 points from three bonus-point wins.
South Africa, Argentina and Australia have one win each, with South Africa second on the table courtesy of two bonus points.
When the All Blacks last played South Africa, in Cape Town last year, they scraped home 25-24 to complete a clean sweep of the championship, after comfortably winning the first leg 57-0 in New Zealand.
15 Jordie Barrett; 14 Ben Smith, 13 Anton Lienert-Brown, 12 Ryan Crotty, 11 Rieko Ioane; 10 Beauden Barrett, 9 Aaron Smith; 8 Kieran Read (captain), 7 Sam Cane, 6 Liam Squire; 5 Scott Barrett, 4 Sam Whitelock; 3 Owen Franks, 2 Codie Taylor, 1 Karl Tu'inukuafe.
Substitutes: 16 Liam Coltman, 17 Tim Perry, 18 Ofa Tu'ungafasi, 19 Patrick Tuipulotu, 20 Ardie Savea, 21 TJ Perenara, 22 Jack Goodhue, 23 Damian McKenzie
15 Willie le Roux, 14 Jesse Kriel 13 Lukhanyo Am, 12 Damian de Allende, 11 Aphiwe
Dyantyi, 10 Handré Pollard, 9 Faf de Klerk, 8 Warren Whiteley, 7 Pieter-Steph
du Toit, 6 Siya Kolisi (captain), 5 Franco Mostert, 4 Eben Etzebeth, 3 Frans
Malherbe, 2 Malcolm Marx, 1 Steven Kitshoff
Substitutes: 16 Bongi Mbonambi, 17 Beast Mtawarira, 18 Wilco Louw, 19 RG
Snyman, 20 Francois Louw, 21 Ross Cronjé, 22 Elton Jantjies, 23 Cheslin Kolbe